buildx.yaml

name: buildx

on:
  workflow_dispatch:  # See https://docs.github.com/en/actions/reference/events-that-trigger-workflows#workflow_dispatch
    inputs:
      image_name:
        description: Name of the image to build
        required: true
      image_tag:
        description: Tag of the image to build
        required: true
        default: latest
      pull_before_build:
        description: Pull image before running build
        required: true
        default: "true"

jobs:
  buildx:
    name: buildx
    runs-on: ubuntu-latest
    env:
      IMAGE_NAME: badouralix/${{ github.event.inputs.image_name }}  # Not exactly the correct wording as per https://stackoverflow.com/questions/31115098/what-is-the-difference-between-an-image-and-a-repository
      IMAGE_TAG: ${{ github.event.inputs.image_tag }}
      WORKING_DIRECTORY: ${{ github.event.inputs.image_name }}/${{ github.event.inputs.image_tag }}
    steps:
    - name: Checkout
      uses: actions/checkout@v3  # See https://github.com/actions/checkout

    - name: Validate event inputs
      uses: actions/github-script@v6  # See https://github.com/actions/github-script
      with:
        script: |
          for (const [key, value] of Object.entries(context.payload.inputs)) {
            core.notice(value, {title: key})
          }

          if (context.ref !== 'refs/heads/main') {
            core.setFailed(`Invalid git branch (expected 'refs/heads/main', got '${context.ref}').`)
            return
          }

          const fs = require('fs')
          const image_name = context.payload.inputs.image_name
          const image_tag = context.payload.inputs.image_tag

          if (!fs.existsSync(image_name) || !fs.statSync(image_name).isDirectory()) {
            core.setFailed(`Invalid image name '${image_name}'.`)
            return
          }

          if (!fs.existsSync(`${image_name}/${image_tag}`) || !fs.statSync(`${image_name}/${image_tag}`).isDirectory()) {
            core.setFailed(`Invalid image tag '${image_tag}' with image name '${image_name}'.`)
            return
          }

    - name: Set up qemu
      uses: docker/setup-qemu-action@v2  # See https://github.com/docker/setup-qemu-action

    - name: Set up buildx
      uses: docker/setup-buildx-action@v2  # See https://github.com/docker/setup-buildx-action

    - name: Login to dockerhub
      uses: docker/login-action@v2  # See https://github.com/docker/login-action
      with:
        username: ${{ secrets.DOCKERHUB_USERNAME }}
        password: ${{ secrets.DOCKERHUB_TOKEN }}  # Get access token from https://hub.docker.com/settings/security

    # Hack from https://stackoverflow.com/questions/58913512/how-to-give-github-action-the-content-of-a-file-as-input
    - name: Read platforms
      id: read_platforms
      working-directory: ${{ env.WORKING_DIRECTORY }}
      run: |
        echo "platforms=$(cat platforms.txt)" >> $GITHUB_OUTPUT

    # See also https://github.com/docker/metadata-action
    - name: Generate labels
      id: generate_labels
      uses: actions/github-script@v6  # See https://github.com/actions/github-script
      with:
        script: |
          const labels = []

          labels.push(`com.github.actions.event_name=${context.eventName}`)
          labels.push(`com.github.actions.job=${context.job}`)
          labels.push(`com.github.actions.run_id=${context.runId}`)
          labels.push(`com.github.actions.run_url=${context.payload.repository.html_url}/actions/runs/${context.runId}`)

          labels.push(`org.opencontainers.image.created=${new Date().toISOString()}`)
          labels.push(`org.opencontainers.image.documentation=${context.payload.repository.html_url}/tree/${context.sha.substr(0,7)}/${context.payload.inputs.image_name}/README.md`)
          labels.push(`org.opencontainers.image.revision=${context.sha}`)
          labels.push(`org.opencontainers.image.source=${context.payload.repository.html_url}`)

          core.startGroup('Generated labels')
          for (const label of labels) {
            core.info(label)
          }
          core.endGroup()

          core.setOutput('labels', labels.join('\n'))

    - name: Run pre build hook
      id: pre_build
      working-directory: ${{ env.WORKING_DIRECTORY }}
      run: |
        if [[ -f hooks/pre_build ]]; then ./hooks/pre_build; fi

    - name: Build and push
      uses: docker/build-push-action@v4  # See https://github.com/docker/build-push-action
      with:
        context: ${{ env.WORKING_DIRECTORY }}
        labels: |
          ${{ steps.generate_labels.outputs.labels }}
          ${{ steps.pre_build.outputs.extra_labels }}
        platforms: ${{ steps.read_platforms.outputs.platforms }}
        pull: ${{ github.event.inputs.pull_before_build }}
        push: true
        tags: |
          ${{ env.IMAGE_NAME }}:${{ env.IMAGE_TAG }}
          ${{ steps.pre_build.outputs.extra_tags }}